Heart valve assembly

ABSTRACT

A heart valve assembly has a heart valve assembly that has a wire frame comprising an anchor section, a generally cylindrical valve support section, and a neck section that transitions between the anchor section and the valve support section. The wire frame includes a plurality of supports extending radially outwardly in an annular manner about an upper end of the valve support section, and the anchor section has an annular flange that extends radially therefrom, so that an annular space is defined between the annular flange and the annular supports for receiving or capturing the native annulus when the heart valve is deployed. The heart valve assembly also includes a leaflet assembly having a plurality of leaflets that are stitched to the valve support section and which are positioned on an inflow side of the neck section.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention is directed to methods, systems, and apparatus forsafely replacing or repairing native heart valves with prosthetic heartvalves.

2. Description of the Prior Art

Prosthetic heart valves have been used for many years to treat cardiacvalvular disorders. The native heart valves (such as the aortic,pulmonary, and mitral valves) serve critical functions in assuring theforward flow of an adequate supply of blood through the cardiovascularsystem. These heart valves can be rendered less effective by congenital,inflammatory, or infectious conditions. Such conditions can eventuallylead to serious cardiovascular compromise or death. For many years thedefinitive treatment for such disorders was the surgical repair orreplacement of the valve during open heart surgery, but such surgeriesare dangerous and prone to complication.

More recently a transvascular technique has been developed forintroducing and implanting a prosthetic heart valve using a flexiblecatheter in a manner that is less invasive than open heart surgery. Inthis technique, a prosthetic valve is mounted in a crimped state on theend portion of a flexible catheter and advanced through a blood vesselof the patient until the valve reaches the implantation site. The valveat the catheter tip is then expanded to its functional size at the siteof the defective native valve, such as by inflating a balloon on whichthe valve is mounted. Alternatively, the valve can have a resilient,self-expanding stent or frame that expands the valve to its functionalsize when it is advanced from a delivery sheath at the distal end of thecatheter.

Unlike the aortic valve, however, the mitral valve annulus does notprovide a good landmark for positioning a replacement mitral valve. Inpatients needing a replacement aortic valve, the height and width of theaortic annulus are generally increased in the presence of degenerativedisease associated with calcium formation. These changes in tissue makeit easier to properly secure a replacement aortic valve in place due tothe reduced cross-sectional area of the aortic annulus. The degenerativechanges typically found in aortic valves are not, however, present inmitral valves experiencing regurgitation, and a mitral valve annulus istherefore generally thinner than the annulus of a diseased aortic valve.The thinner mitral valve annulus makes it relatively more difficult toproperly seat a replacement mitral valve in the native mitral valveannulus. The general anatomy of the mitral valve annulus also makes itmore difficult to properly anchor a replacement mitral valve in place.The mitral valve annulus provides for a smoother transition from theleft atrium to the left ventricle than the transition that the aorticvalve annulus provides from the aorta to the left ventricle. The aorticannulus is anatomically more pronounced, providing a larger “bump” towhich a replacement aortic valve can more easily be secured in place.

Thus, the larger mitral valve annulus makes it difficult to securelyimplant current percutaneously delivered valves in the native mitralposition. Some attempts have been made to deliver and implant aone-piece replacement mitral valve, but it is difficult to provide adevice that can be collapsed down to have a sufficiently small deliveryprofile and still be able to be expanded and secured in place within themitral valve via a vascular access site.

As a result, there remains a need for a replacement mitral valve thathas a valve support structure or anchoring device that can be positionednear or within the native mitral valve.

SUMMARY OF THE DISCLOSURE

To accomplish the objectives set forth above, the present inventionprovides a heart valve assembly that has a wire frame comprising ananchor section, a generally cylindrical valve support section, and aneck section that transitions between the anchor section and the valvesupport section. The wire frame includes a plurality of supportsextending radially outwardly in an annular manner about an upper end ofthe valve support section, and the anchor section has an annular flangethat extends radially therefrom, so that an annular space is definedbetween the annular flange and the annular supports for receiving orcapturing the native annulus when the heart valve is deployed. The heartvalve assembly also includes a leaflet assembly having a plurality ofleaflets that are stitched to the valve support section and which arepositioned on an inflow side of the neck section. The heart valveassembly can be secured at the location of the native annulus of a humanheart by delivering the heart valve assembly to the location of a nativeannulus, and deploying the heart valve assembly at the location of thenative annulus with the native annulus retained inside the annularspace.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a valve device according to one embodiment ofthe present invention shown in an expanded configuration.

FIG. 2 is a bottom view of the device of FIG. 1, shown with the valve ina fully closed position with pressure on the leaflets.

FIG. 3 is a top view of the device of FIG. 1, shown with the valve in afully closed position with pressure on the leaflets.

FIG. 4 is a side view of the wire frame of the device of FIG. 1.

FIG. 5 is a top view of the wire frame of FIG. 4.

FIG. 6 is a bottom view of the wire frame of FIG. 4.

FIG. 7 illustrates a delivery system that can be used to deploy thedevice of FIG. 1.

FIGS. 8A-8E illustrate how the device of FIG. 1 can be deployed at themitral annulus of a patient's heart using a transapical delivery system.

FIG. 9 is a side view of a valve device according to another embodimentof the present invention shown in an expanded configuration.

FIG. 10 is a top view of the device of FIG. 9, shown with the valve in afully closed position with pressure on the leaflets.

FIG. 11A is a cut-away side view of the device of FIG. 9 after it hasimplanted in a native valve annulus.

FIG. 11B is a side view of the device of FIG. 9 before it has implantedin a native valve annulus.

FIG. 11C is a side view of the valve assembly for the device of FIG. 9.

FIG. 12 is a side view of the wire frame of the device of FIG. 9.

FIG. 13 is a side view of the anchor piece of the wire frame of FIG. 12.

FIG. 14 is a side view of the valve support piece of the wire frame ofFIG. 12.

FIG. 15 illustrates the device of FIG. 9 in a compressed configuration.

FIGS. 16A-16D illustrate how the device of FIG. 9 can be deployed at themitral annulus of a patient's heart using a transapical delivery system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description is of the best presently contemplatedmodes of carrying out the invention. This description is not to be takenin a limiting sense, but is made merely for the purpose of illustratinggeneral principles of embodiments of the invention. The scope of theinvention is best defined by the appended claims.

The present invention provides a mitral valve device 100 that is shownin fully assembled form in FIGS. 1-3. The device 100 has a wire frame101 (see FIGS. 4-6) that is adapted to carry an integrated leafletassembly that comprises a plurality of leaflets 106. The wire frame 101provides a simple leaflet valve support structure that can beeffectively secured at the native mitral valve annulus. The overallconstruction of the device 100 is simple, and effective in promotingproper mitral valve function.

As shown in FIGS. 4-6, the wire frame 101 comprises an (outflow) anchorsection 104 that transitions to a generally cylindrical valve supportsection 108 via a neck section 107. The different sections 104, 107 and108 can be made of one continuous wire, and can be made from a thin wallbiocompatible metallic element (such as stainless steel, Co—Cr basedalloy, Nitinol™, Ta, and Ti etc.). As an example, the wire can be madefrom a Nitinol™ wire that is well-known in the art, and have a diameterof 0.2″ to 0.4″. These sections 104, 107 and 108 define open cells 109within the wire frame 101. Each cell 109 can be defined by a pluralityof struts 103 that encircle the cell. In addition, the shapes and sizesof the cells 109 can vary between the different sections 104, 107 and108.

The valve support section 108 functions to hold and support the leaflets106, and has an inflow end that is configured with an annular zig-zagarrangement of inflow tips 116. The zig-zag arrangement defines peaks(i.e., the tips 116) and valleys (inflection points 113). As shown inFIG. 1, the leaflets 106 can be sewn directly to the struts 103 of thecells 109 in the valve support section 108.

A plurality of V-shaped annular supports 105 extend radially outwardlyin an annular manner about the upper end of the valve support section108. These supports 105 extend radially outwardly and upwardly at aslight angle. The upper end of the valve support 108 also transitionsinto the neck section 107 which first extends radially inwardly, andthen continues to curve back radially outwardly as it transitions intothe anchor section 104. In other words, the neck section 107 isconfigured as an annular U-shaped section.

The anchor section 104 functions to secure or anchor the valve device100, and specifically the wire frame 101, to the native valve annulus ofthe human heart. The anchor 104 has a flared and bowl-shapedconfiguration where it defines an annular flange 111 that extendsradially outwardly from the neck section 107 to an outer-most annularline 112 where its diameter is greatest, and then curves radiallyinwardly to an annular zig-zag arrangement of outflow tips 117 at itsuppermost periphery. The zig-zag arrangement defines peaks (i.e., thetips 117) and valleys. All portions of the anchor section 104 have awider diameter than the neck section 107 and valve support section 108.The outer diameter of the V-shaped supports 105 is also less than theouter-most diameter of the anchor section 104 at the annular line 112.An annular space S1 is defined between the flange 111 and the V-shapedsupports 105.

The following are some exemplary and non-limiting dimensions for thedevice 100. For example, the outer diameter for the annular line 112 canbe 50 mm; the outer diameter of the V-shaped supports 105 can be 40 mm;the inner diameter of the neck section 107 can be 30 mm; and the outerdiameter of the valve support section 108 can be 30 mm. In addition, thelength of the valve support section 108 can vary depending on the numberof leaflets 106 are supported therein. For example, in the embodimentillustrated in FIGS. 1-3 where four leaflets 106 are provided, thelength of the valve support section 108 can be about 12-14 mm. If threeleaflets 106 are provided, the length of the valve support section 108would need to be longer, such as 15-18 mm. The height of the space S1can be 5 mm, and the height H1 of the anchor section 104 can be 5 mm.These exemplary dimensions can be used for a device 100 that is adaptedfor use at the native mitral valve location for a generic adult andthese dimensions will vary for devices 100 that are used for otherapplications, such as for an aortic or tricuspid valve. These exemplarydimensions illustrate the proportions of the various elements to eachother.

Referring to FIGS. 1-3, the leaflet assembly includes the actualleaflets 106 as well as a number of skirts. For example, an upper skirt132 can be sewn to the struts 103 in the anchor section 104 to cover theflange 111 and the rest of the anchor section 104; an intermediate neckskirt 142 can be sewn to the struts 103 in the neck section 107 to coverthe neck section 107, and a lower annulus skirt 152 can be sewn to theV-shaped supports 105 to cover the cells in the V-shaped supports 105.The leaflets 106 can be sewn directly to the struts 103 of the cells 109in the valve support section 108. The leaflets 106 and the skirts 132,142 and 152 can be made of the same material. For example, the materialcan be a treated animal tissue such as pericardium, or frombiocompatible polymer material (such as PTFE, Dacron, bovine, porcine,etc.). The leaflets 106 and the skirts 132, 142 and 152 can also beprovided with a drug or bioagent coating to improve performance, preventthrombus formation, and promote endothelialization, and can also betreated (or be provided) with a surface layer/coating to preventcalcification.

The device 100 of the present invention can be compacted into a lowprofile and loaded onto a delivery system, and then delivered to thetarget location by a non-invasive medical procedure, such as through theuse of a delivery catheter through transapical, or transfemoral, ortranseptal procedures. The device 100 can be released from the deliverysystem once it reaches the target implant site, and can expand to itsnormal (expanded) profile either by inflation of a balloon (for aballoon expandable wire frame 101) or by elastic energy stored in thewire frame 101 (for a device where the wire frame 101 is made of aself-expandable material).

FIGS. 8A-8E illustrate how the device 100 can be deployed at the mitralannulus of a patient's heart using a transapical delivery. Referringfirst to FIG. 7, the delivery system includes a delivery catheter 2000that has a distal tip 2015 which is connected to the ear hub 2030 of theinner core 2025. The catheter 2000 has an outer shaft 2004 that isconnected to a handle (not shown), and the outer shaft 2004 includes acapsule 2010. The device 100 is crimped and loaded on the inner core2025 below the tip 2015, and then covered by the capsule 2010.

Referring now to FIG. 8A, the device 100 is shown in a collapsedconfiguration being delivered to the mitral annulus inside the capsule2010. In FIG. 8B, the capsule 2010 is withdrawn (i.e., moved downwardly)with respect to the inner core 2025 (and the device 100 that is carriedon the inner core 2025) to partially expose the device 100 so that theself-expanding wire frame 101 will deploy the anchor section 104 in theatrium, and at a location above the native annulus 8. In FIG. 8C, thecapsule 2010 is shown as being further withdrawn to release the V-shapedsupports 105 at a location below the native annulus 8. This will allowthe native annulus 8 to be captured or received in the space S1 betweenthe flange 111 and the V-shaped supports 105. In FIG. 8D, the capsule2010 is shown as being further withdrawn to release the valve supportsection 108. FIG. 8E shows the device 100 being fully deployed at thenative annulus 8, and with the distal tip 2015 and capsule 2010 beingwithdrawn with the rest of the delivery system.

Thus, when the device 100 is deployed, the native annulus 8 is capturedor received in the space S1 to create a “seal” to prevent leakage (bloodflow back from the left ventricle to the left atrium) from the areasurrounding the device 100. In addition, the V-shaped supports 105 pushaside the native anterior leaflet 10 and the native posterior leaflet 12against the wall of the ventricle.

FIGS. 9-14 illustrate a second embodiment of a mitral valve device 200that is shown in fully assembled form in FIGS. 9, 10, 11A and 11B. Thedevice 200 is similar to the device 100 above, except that the one-piecewire frame 101 is now replaced by a wire frame that is made up of twoseparate pieces: an anchor piece 204 (see FIG. 13) and a valve supportpiece 208 (see FIG. 14) that can be fitted together. The combined anchorpiece 204 and valve support piece 208 is also adapted to carry anintegrated leaflet assembly that comprises a plurality of leaflets 206.

As shown in FIGS. 12-14, the wire frame comprises an anchor piece 204and a valve support piece 208. Each piece 204 and 208 can be made of onecontinuous wire, and can be made from a thin wall biocompatible metallicelement (such as stainless steel, Co—Cr based alloy, Nitinol™, Ta, andTi etc.). As an example, the wire can be made from a Nitinol™ wire thatis well-known in the art, and have a diameter of 0.2″ to 0.4″. Thesepieces 204 and 208 also define open cells 209 within the wire frame.Each cell 209 can be defined by a plurality of struts 203 that encirclethe cell. In addition, the shapes and sizes of the cells 209 can varybetween the different pieces 204 and 208.

Referring to FIG. 14, the valve support piece 208 functions in the sameway as the valve support section 108, which is to hold and support theleaflets 206. The valve support piece 208 is defined by a cylindricalbody 201, and has an inflow end that is configured with an annularzig-zag arrangement of inflow tips 219. At its opposite end, a neck area218 is defined by an annular concave (U-shaped) section of thecylindrical body 201, and terminates at an outflow end that isconfigured with an annular zig-zag arrangement of outflow tips 215. Thezig-zag arrangement defines peaks (i.e., the tips 215 and 219) andvalleys (inflection points 211).

Referring to FIG. 13, the anchor piece 204 also functions to secure oranchor the valve device 200, and specifically the wire frame, to thenative valve annulus 8 of the human heart. The anchor piece 204comprises an annular ring of cells 209 that are configured to define anannular concave (U-shape) belt having an annular zig-zag arrangement ofinflow tips 217, and an annular zig-zag arrangement of outflow tips 210,with a neck region 216 defined therebetween. The zig-zag arrangementdefines peaks (i.e., the tips 210 and 217) and valleys (inflectionpoints 212).

As best shown in FIG. 12, the anchor piece 204 is coupled to the valvesupport piece 208 by inserting the outflow end of the valve supportpiece 208 through the anchor piece 204, with the tips 215 engaging theinflection points 212 between adjacent tips 210 on the anchor piece 204.When the pieces 204 and 208 are coupled in the manner shown in FIG. 12,the neck region 216 functions in the same way as the neck section 107,and the tips 217 function in the same manner as the V-shaped supports105. The outer diameters defined by the tips 210 and 217 of the anchorpiece 204 are wider than the largest diameter of any part of the body201 of the valve support piece 208. The outer diameter defined by thetips 217 is also less than the outer diameter defined by the tips 210.An annular space S2 is defined between the tips 210 and 217.

The following are some exemplary and non-limiting dimensions for thedevice 200. For example, the outer diameter defined by the tips 210 canbe 50 mm; the outer diameter defined by the tips 217 can be 40 mm; theinner diameter of the neck region 216 can be 30 mm; and the outerdiameter of the cylindrical body 210 of the valve support piece 208 canbe 30 mm. In addition, the length of the valve support piece 208 canvary depending on the number of leaflets 206 are supported therein. Forexample, in the embodiment illustrated in FIGS. 9-11C where threeleaflets 206 are provided, the length of the cylindrical body 201 can beabout 15-20 mm. If four leaflets 206 are provided, the length of thevalve support piece 208 could be shorter, such as less then 14 mm. Theheight of the space S2 can be 5 mm and the height H2 of the anchor piece204 can be 10 mm. These exemplary dimensions can be used for a device200 that is adapted for use at the native mitral valve location for ageneric adult and these dimensions will vary for devices 200 that areused for other applications, such as for an aortic or tricuspid valve.These exemplary dimensions illustrate the proportions of the variouselements to each other.

Referring to FIGS. 9, 10, 11A, 11B and 15, the leaflet assembly includesthe actual leaflets 206 as well as a number of skirts. For example, anupper annulus skirt 220 can be sewn to the struts 203 in the anchorpiece 204 to cover the cells 209 and spaces between the tips 210; alower annulus skirt 221 can be sewn to the struts 203 in the anchorpiece 204 to cover the spaces between the tips 217; a valve supportskirt 222 can be sewn to the struts 203 to cover the cells 209 in thecylindrical body 201; a connection skirt 223 can be sewn to the anchorpiece 204 and the valve support piece 208 to connect these two pieces204 and 208; and a valve seal skirt 224 can be sewn to the cells 209 inthe neck area 218 extending from the inflection points 211 to the tips215. As best shown in FIGS. 11A-11C, the connection skirt 223 can besewn inside the anchor piece 204 and continue down the inner surface ofthe valve support piece 208. The valve support piece 208 can be insertedinside the anchor piece 204, and the connection skirt 223 can be foldedoutside the valve support piece 208 at the location of the tips 215 atthe neck area 218 to create two layers of the connection skirt 223 atthe location of the neck area 218. In fact, the neck region 216 of theanchor piece 204 actually has three layers of skirt material (i.e.,tissue): the lower annulus skirt 221 and the overlapping layers of theconnection skirt 223. These three layers provide a better seal. Theleaflets 206 can be sewn directly to the struts 203 of the cells 209 inthe cylindrical body 201. The leaflets 206 and the skirts 220, 221, 222,223 and 224 can be made of the same material(s) as those describedconnection with the leaflets 106 above.

As with the device 100, the device 200 can be compacted into a lowprofile and loaded onto a delivery system, and then delivered to thetarget location by a non-invasive medical procedure, such as through theuse of a delivery catheter through transapical, or transfemoral, ortranseptal procedures. The device 200 can be released from the deliverysystem once it reaches the target implant site, and can expand to itsnormal (expanded) profile either by inflation of a balloon, or byelastic energy stored in the wire frame 101.

FIGS. 16A-16D illustrate how the device 200 can be deployed at themitral annulus of a patient's heart using a transapical delivery, andthe delivery catheter 2000 of FIG. 7. Referring first to FIG. 15, thedevice 200 is shown in its compressed configuration. The device 200 ascollapsed can be loaded inside the same delivery catheter 2000 that isshown and described in FIG. 7. The device 200 can be crimped and loadedon the inner core 2025 below the tip 2015, and then covered by thecapsule 2010.

Referring now to FIG. 16A, the device 200 is shown in a collapsedconfiguration being delivered to the mitral annulus inside the capsule2010. In FIG. 16B, the capsule 2010 is withdrawn (i.e., moveddownwardly) with respect to the inner core 2025 to partially expose thedevice 200 so that the self-expanding wire frame will deploy the anchorpiece 204 in the atrium, and at a location above the native annulus 8.In FIG. 16C, the capsule 2010 is shown as being further withdrawn torelease the valve support piece 208. FIG. 16D shows the device 200 beingfully deployed at the native annulus 8, and with the capsule 2010 andouter shaft 2015 being withdrawn with the rest of the delivery system.

Thus, when the device 200 is deployed, the native annulus 8 is capturedor received in the space S2 between the tips 210 and 217 to create a“seal” to prevent leakage (blood flow back from the left ventricle tothe left atrium) from the area surrounding the device 200. In addition,the tips 217 push aside the native anterior leaflet 10 and the nativeposterior leaflet 12 against the wall of the ventricle.

The devices 100 and 200 of the present invention provide a number ofbenefits. First, the manner in which the device 100 is anchored to thenative annulus 8 allows the chordae to be free. Second, the devices 100and 200 do not block blood flow to the aortic valve. Specifically, whenthe anchor piece 204 is first deployed at the native annulus, itfunctions as a secure anchor ring after the valve support piece 208 isinserted and moved up by at least 10 mm. As a result, it is possible toprovide the cylindrical body 201 with a short length that minimizesblockage of blood flow. Third, the anchor piece 204 functions as anannulus ring to prevent rocking of the device 200 when the valves openand close, because the device 200 is provided in two separate pieces 204and 208.

Even though the present invention has been described in connection withuse as a mitral replacement valve, the devices 100 and 200 can also beused as an aortic or tricuspid valve. Specifically, when used as anaortic valve, the device 100 or 200 can be reversed by 180 degrees. Thetricuspid location is the same as the mitral position, so the sameprinciples described above would apply as well.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The accompanying claimsare intended to cover such modifications as would fall within the truescope and spirit of the present invention.

What is claimed is:
 1. A heart valve assembly, comprising: a wire framecomprising: an anchor section having a flared and bowl-shapedconfiguration which defines an annular flange; a generally cylindricalvalve support section; and a neck section that transitions between theanchor section and the valve support section, the wire frame furthercomprising a radial ring that extends radially outwardly in an annularmanner about an upper end of the valve support section, the radial ringconsisting only of a plurality of V-shaped supports that extend radiallyoutwardly and upwardly at an angle; wherein an annular space is definedbetween the annular flange and the V-shaped supports; wherein the upperend of the valve support section transitions into the neck section whichfirst extends radially inwardly, and then continues to curve backradially outwardly to transition into the anchor section so that theneck section is configured as an annular U-shaped section; and whereinthe annular flange extends radially outwardly from the neck section toan outer-most annular line, and then curves radially inwardly to anannular zig-zag arrangement of outflow tips that defines peaks andvalleys; a leaflet assembly having a plurality of leaflets that arestitched to the valve support section and which are positioned on aninflow side of the neck section; and wherein the anchor sectionfunctions to secure the wire frame to a native valve annulus of a humanheart.
 2. The assembly of claim 1, wherein the anchor section has awider diameter than a diameter of each of the plurality of V-shapedsupports, the neck section and the valve support section.
 3. Theassembly of claim 2, wherein the V-shaped supports have an outerdiameter that is less than an outer-most diameter of the anchor sectionat the annular line.
 4. The assembly of claim 1, wherein the anchorsection, the neck section and the valve support section are all providedin a single piece.
 5. The assembly of claim 1, wherein the plurality ofleaflets comprises three or four leaflets.
 6. The assembly of claim 1,further including a skirt connected to the anchor section and the necksection.
 7. The assembly of claim 1, wherein the valve support sectionhas an inflow end that is configured with an annular zig-zag arrangementthat defines peaks and valleys.